The invention relates to a two-stage exhaust gas turbocharging arrangement for an internal-combustion engine.
The invention is based on German Published Patent Application DE 10 2006 011 188 A1. From DE 10 2006 011 188 A1, a two-stage exhaust gas turbocharging arrangement is known for an internal-combustion engine having an exhaust manifold. In the flow direction of the exhaust gas of the internal-combustion engine, the exhaust gas turbocharging arrangement has smaller first and second high-pressure turbochargers, which are arranged parallel to one another, and additionally a larger low-pressure turbocharger arranged in series behind the latter. The exhaust manifold, the first high-pressure turbine housing of the first high-pressure turbocharger and the low-pressure turbine housing of the low-pressure turbocharger are mutually connected in an exhaust-gas-bearing manner. In addition, the exhaust manifold can be connected with the second high-pressure turbine housing of the second high-pressure turbocharger in an exhaust-gas-bearing manner by way of a throttling element, while the first high-pressure turbine housing and the low-pressure turbine housing are permanently connected with one another in an exhaust-gas-bearing manner.
By means of the two-stage exhaust gas turbocharging arrangement of the above-mentioned type, very high power densities can be achieved for an internal-combustion engine. Except for relatively high component expenditures and a relatively large size, this arrangement has no disadvantages.
It is an object of the present invention to achieve a design that is as compact as possible (for the purpose of packaging) for a two-stage exhaust gas turbocharging arrangement of the above-mentioned type.
This object is achieved by way of a two-stage exhaust gas turbocharging arrangement for an internal-combustion engine having an exhaust manifold. In the flow direction of an exhaust gas of the internal-combustion engine, the exhaust gas turbocharging arrangement having a first high-pressure turbocharger and a second high-pressure turbocharger arranged parallel to one another, and a low-pressure turbocharger arranged in series behind the latter. The exhaust manifold, a first high-pressure turbine housing of the first high-pressure turbocharger and a low-pressure turbine housing of the low-pressure turbocharger are connected with one another in an exhaust-gas-bearing manner. The exhaust manifold is connectable in an exhaust-gas-bearing manner with a second high-pressure turbine housing of the second high-pressure turbocharger, and the second high-pressure turbine housing and the low-pressure turbine housing are connected with one another in an exhaust-gas-bearing manner. The two high-pressure turbine housings are arrangeable on the exhaust manifold on one side and the low-pressure turbine housing can be arranged on the exhaust manifold on the other side. The exhaust gas coming from the high-pressure turbine housings is guided through a flow duct in or on the exhaust manifold to the low-pressure turbine housing.
As a result of the development according to the invention, a packaging advantage as well as a cost advantage is achieved.
In one preferred aspect of the invention, the first and second high-pressure turbine housings are detachably connectable with the exhaust manifold. This embodiment represents a particularly preferred service-friendly mounting possibility. This may, for example, be a proven screwed connection.
Further aspects according to the invention have the first and second high-pressure turbine housings made in one piece and of a uniform material. Moreover, a first air charge cooler may be provided for the low pressure exhaust gas turbocharger, wherein a low-pressure compressor housing of the low-pressure exhaust gas turbocharger is made in one piece with a housing of the first charge air cooler. These embodiments further reduce the component expenditures and therefore the costs.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.